A scientist has thought up of a formula to calculate the worth of planet Earth and has valued it at 3,000 trillion pounds.Astrophysicist Greg Laughlin came up with the figure by calculating the sum of the planet’s age, size, temperature, mass and other vital statistics—and Earth came out as the most expensive.Mars was only valued at 10,000 pounds, while Venus is said to be worth less than a penny. There are about 1,235 other planets in existence, whose inhospitable climes ruled out a higher price tag.Laughlin from the University of California in the US used his equation to evaluate the discoveries made by NASA’s 600 million pounds Kepler spacecraft, the Daily Mail reported.The planet-hunting spacecraft went into orbit two years ago and a year later Laughlin decided to create price tags for the terrestrial planets that Keplar was set to discover, according to a California University statement.At the time, the exoplanet Gilese 581 c was considered the most Earth-like world known to scientists, but the equation only valued it at 100 pounds, while KOI 326.01 is said to be worth 150,000 pounds – Khaleejnews